his is the second post in a series by Michelle C. of IntentionalTravelers.com. Michelle and her husband have found creative ways to exponentially increase the amount they can travel. In her first post of the series, Michelle explained how being digital nomads with a flexible schedule allows them to work as they travel and keep costs low. Part 2 covered tips for saving big on accommodation costs. Today's installment reveals how to find cheap (and even free) airline flights.

Transportation is often one of the biggest expenses that eats into the budget of a trip. With round-trip flights from Europe, Jamaica, and twice to Hawaii last year for both myself and my husband, you'd think we shelled out thousands of dollars. Actually, for both of our international trips, we paid only nominal fees, and we saved over $1200 on our Hawaii flights. But more about that later...

Here are some of our favorite tricks and tools for finding cheap flights:

I use this high-powered search tool, created by Google, to research possible flight itineraries. You can't book tickets from the site, but it has highly customizable search options and covers just about every flight out there. If you want to patch together a complicated route from various airlines, or find the best deal on business class for a six-day trip any time in April, you can do that and more with this site.

If you want to keep tabs on unusually low airfares, this site publishes deals as soon as they become available. You can filter the posts for departures out of major cities like Portland and Seattle. If you have an upcoming vacation and haven't decided where to go yet, this would be a good place to find inspiration and savings on your next destination.

For simple travel itineraries, we like Kayak's search tool. And their Explore page is a fun way to find the cheap fares from your local airport when you don’t have a particular destination in mind. Want to go somewhere sunny in December? You can search by month and by weather on Kayak Explore and compare prices.

Hands down, the biggest way we've been able to exponentially increase our travel is through the accumulation of reward points and frequent flyer miles. It's often referred to as "travel hacking" (though I can assure, it is a legitimate endeavor completely unrelated to actual hacking!). Starting small with the Alaska Airlines award program and two credit card sign-up bonuses each, we learned the ropes with the Frequent Flyer Master guide. Created by Chris Guillebeau, a young author and entrepreneur who recently finished his quest to see every country in the world, this e-guide showed us everything we needed to know to quickly earn free flights.

Travel hacking does have a learning curve and takes some work, but a little extra effort goes a long way. If you can stay organized and are responsible with credit (i.e. pay off your credit cards in full every month), then I highly recommend this method for making your travel dreams come true. To learn more about how we got started in this "hobby," see our post on travel hacking with the Alaska Airlines award program.